Light emitting diode and fabrication method thereof

Abstract

A light-emitting diode includes a light-emitting epitaxial laminated layer and an omnidirectional reflector structure. The light-emitting epitaxial laminated layer has a first surface and an opposing second surface, including an n-type semi-conductive layer, a light emitting layer and a p-type semiconductor layer. The omnidirectional reflector structure is formed on the second surface of the light-emitting epitaxial laminated layer, including: a transparent dielectric layer on the second surface of the light-emitting epitaxial laminated layer and having conductive holes therein; a first transparent adhesive layer on one side surface of the transparent dielectric layer distal from the light-emitting epitaxial laminated layer and covering side walls of the conductive holes; a second transparent adhesive layer on one side surface of the first transparent adhesive layer distal from the transparent dielectric layer; and a metal reflective layer on one side of the second transparent adhesive layer distal from the first transparent adhesive layer.

The invention claimed is: 
     
       1. A light-emitting diode (LED), comprising:
 a light-emitting epitaxial laminated layer, having a first surface and a second surface that are opposite to each other, comprising an n-type semiconductor layer, a light emitting layer, and a p-type semiconductor layer; 
 an omnidirectional reflector structure is formed on the second surface of the light-emitting epitaxial laminated layer, comprising a transparent dielectric layer located on the second surface of the light-emitting epitaxial laminated layer and having conductive holes therein; 
 a first transparent adhesive layer on one side surface of the transparent dielectric layer that is distal from the light-emitting epitaxial laminated layer, and covers side walls of the conductive holes; 
 a second transparent adhesive layer on one side surface of the first transparent adhesive layer that is distal from the transparent dielectric layer; and 
 a metal reflective layer on one side surface of the second transparent adhesive layer that is distal from the first transparent adhesive layer. 
 
     
     
       2. The LED of  claim 1 , wherein a thickness of the transparent dielectric layer is larger than 50 nm. 
     
     
       3. The LED of  claim 1 , wherein the first transparent adhesive layer is a transparent isolating adhesive layer covering one side surface of the transparent dielectric layer that is distal from the light-emitting epitaxial laminated layer. 
     
     
       4. The LED of  claim 1 , wherein a thickness of the first transparent adhesive layer is less than 20 nm. 
     
     
       5. The LED of  claim 1 , wherein the second transparent adhesive layer is a transparent conductive adhesive layer. 
     
     
       6. The LED of  claim 5 , wherein a thickness of the second transparent adhesive layer is less than 10 nm. 
     
     
       7. The LED of  claim 5 , wherein a thickness of the first transparent adhesive layer is less than 1/10 of the thickness of the transparent dielectric layer. 
     
     
       8. The LED of  claim 1 , wherein the transparent dielectric layer is composed of a plurality of sub-layers, wherein, thickness of the first transparent adhesive layer is less than ⅕ of the thickness of any sub-layer of the transparent dielectric layer. 
     
     
       9. The LED of  claim 1 , wherein the transparent dielectric layer is an MgF layer; the first transparent adhesive layer is a SiO layer; the second transparent adhesive layer is a sputtered ITO layer; and the metal reflective layer is an Ag reflector. 
     
     
       10. The LED of  claim 1 , further comprising a diffusion blocking layer wrapping a surface and a side wall at the side of the metal reflective layer that is distal from the light-emitting epitaxial laminated layer. 
     
     
       11. The LED of  claim 1 , wherein the conductive holes are filled with a metal ohmic contact layer, wherein, the surface at the side that is distal from the epitaxial laminated layer is flush with the first transparent adhesive layer. 
     
     
       12. A light emitting diode (LED), comprising a light-emitting epitaxial laminated layer and an omnidirectional reflector structure, wherein:
 the light-emitting epitaxial laminated layer has a first surface and a second surface that are opposite to each other, comprising an n-type semi-conductive layer, a light emitting layer and a p-type semiconductor layer; 
 the omnidirectional reflector structure is formed on the second surface of the light-emitting epitaxial laminated layer, comprising: 
 a transparent dielectric layer on the second surface of the light-emitting epitaxial laminated layer and having conductive holes therein, at least comprising a first layer and a second layer; 
 the first layer is adjacent to the light-emitting epitaxial laminated layer, and the second layer is distal from the light-emitting epitaxial laminated layer, wherein the second layer has a thickness less than 1/10 that of the first layer, and serves as an adhesive layer of the first layer; and 
 a transparent conductive adhesive layer on the surface of the second sub-layer of the transparent dielectric layer; and a metal reflective layer on one side surface of the transparent conductive adhesive layer that is distal from the transparent dielectric layer. 
 
     
     
       13. The LED of  claim 12 , wherein the first layer comprises a plurality of sub-layers, wherein, a thickness of the second layer is less than ⅕ of the thickness of any sub-layer of the first layer. 
     
     
       14. The LED of  claim 12 , wherein a thickness of the first layer appears gradual distribution, wherein, thickness of the layer adjacent to the light-emitting epitaxial laminated layer is at maximum and decreases gradually. 
     
     
       15. The LED of  claim 12 , wherein a thickness of the first layer is larger than 50 nm. 
     
     
       16. The LED of  claim 12 , wherein a thickness of the second layer is less than 20 nm. 
     
     
       17. The LED of  claim 12 , wherein a thickness of the transparent conductive adhesive layer is less than 10 nm. 
     
     
       18. The LED of  claim 12 , wherein the first layer is an MgF layer; the second layer is a SiO layer; the transparent conductive adhesive layer is an ITO layer; and the metal reflective layer is an Ag reflector. 
     
     
       19. The LED of  claim 12 , wherein the conductive holes are filled with a metal ohmic contact layer, wherein the surface at the side that is distal from the epitaxial laminated layer is flush with the transparent dielectric layer. 
     
     
       20. The LED of  claim 12 , wherein the light emitting diode also comprises an anti-diffusion protective layer, which wraps the surface and the side wall at the side of the metal reflective layer that is distal from the light-emitting epitaxial laminated layer, and the anti-diffusion protective layer is connected to the metal reflective layer with no gap.